Segment rotary nozzle

ABSTRACT

A device for spraying a liquid has a rotating surface, preferably one with an edge apron which is angled obliquely toward the outside, from whose possibly serrated outer spraying edge the liquid is flung out. The rotating surface is partially covered by a housing which is provided with an opening which leaves a partial circumference free. The device has a reservoir and a flow path for collecting retained drops, in whose circulation a pump is provided which is embodied to reunite collected liquid with the inflowing liquid. A conveying surface of a pump, preferably a friction pump, is disposed coaxially with the axis of rotation of the rotating surface.

BACKGROUND OF THE INVENTION

The invention relates to a device for spraying a liquid, wherein arotating surface is embodied to be partially enclosed by a housing withan opening leaving a partial circumference free, and the device forcollecting retained drops has a reservoir and a flow path in whosecirculation a pump is provided which is embodied to combine collectedliquid with the inflowing liquid.

In previously known devices of this type the drops are flung away on allsides perpendicularly with their axis of rotation by a centrifugal disk.Under the influence of gravity the drops form a so-called spray cone,whose diameter can be affected by the rpm of the centrifugal disk. Toachieve a sufficiently fine and even drop size it is necessary to drivethe centrifugal disk at high rpm of 10,000 to 15,000 revolutions perminute, for example. Although in the process it is possible to achieve avery even drop size of 35 μ, for example, the hollow cone created in thecourse of spraying has a relatively large diameter of, for example, 100to 120 cm, which is undesirable for many purposes.

Such devices are used in agriculture for covering areas with herbicides.In order to be able to treat the areas between the rows of useful plantsin a well-directed manner, it is necessary to set the width of the sprayas exactly as possible and to aim the flow of drops as exactly aspossible toward the surface.

A device for spraying a liquid in accordance with the species is knownfrom U.S. Pat. No. 2,545,489. The rotating surface is partially enclosedin a housing and keeps an opening free over a part of the circumference.It has a reservoir and a flow path for collecting drops which wereretained, in whose circulation a pump is provided for reuniting thecollected liquid with the inflowing liquid.

This pump which returns the collected liquid is embodied as a housingrevolving in the shape of a truncated cone which, driven by a gearwheel, rotates at approximately 1/10 of the rpm of the rotating surface.A second hub, which is inclined in respect to the axis of circulation ofthe rotating surface, is provided for this purpose, as well as areduction gear with gear wheels which reduces the rpm of the shaftcorrespondingly. Finally, this device has a metering device which isembodied in a very complicated manner, which again provides the rotatingsurfaces with the inflowing liquid and the returned liquid partiallyseparated by means of two valve disks.

The British document GB 2 164 270 shows a device wherein the pump isembodied as an axial pump for returning the liquid.

SUMMARY OF THE INVENTION

It is the object of the invention to recite a segment rotary nozzlewhich can be manufactured with reduced expense and further than that hasa longer life expectancy.

This object is attained in accordance with a device of the species inthat a conveying surface of a pump, preferably a friction pump, isdisposed coaxially with the axis of rotation of the rotating surface.The liquid is returned to the rotating surface in a particularlycost-effective and maintenance-free manner by means of this step.Complicated gears can be omitted.

Because the rotating surface and the conveying surface are embodied asparts of a single rotating part, the pump can be manufacturedparticularly advantageously.

It is achieved by the step of the rotating surface having an axis ofrotation which is inclined at an angle in respect to the horizontal thatgravity makes the return of the liquid in the housing easier.

If the opening is embodied to be adjustable it is possible, for example,to also adapt the directed stream exiting through the opening to thedesired spraying width by changing the opening sector. If the positionof the opening is changed it is possible to spray upward, for example.

So that the caught drops can be better collected it is advantageous ifthe housing has bars on the inside for guiding the caught liquid.

The aspiration of the collected liquid at the termination of thespraying work is made easier in that a metering pump for supplying theliquid is associated with the device, whose conveying direction isembodied to be reversible. If further than that it has a line forsupplying liquid which is disposed to terminate in the reservoir, themetering pump provided can in this case also perform the aspiration byreversing the direction of rotation.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained in the drawings, and furtheradvantageous details can be taken from the drawings.

In detail, the drawings show in:

FIG. 1, a vertical section through the nozzle in the operationalposition,

FIG. 2, a top view of the nozzle housing in accordance with the arrowdirection II in FIG. 1,

FIG. 3, a top view of the nozzle cover with the centrifugal disk inaccordance with the arrow direction III in FIG. 1,

FIG. 4, the flow chart of a spraying device, and

FIG. 5, an exploded view of the device in accordance with the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A centrifugal wheel rotating around an axis 2 is identified by 1 inFIG. 1. It has an outer edge in the form of a rotating surface fromwhich drops are flung away. The centrifugal wheel is enclosed by ahousing 3. An opening 4 in the housing extends over a partialcircumference of the centrifugal wheel.

The housing 3 essentially consists of the nozzle body 5 and the cover 6.

Segment aprons 9 and 10 (FIG. 3), which are also displaceable around theaxis 2 along two arc-shaped adjustment openings 17 (FIG. 3), aredisposed in the lateral edge area inside the opening 4 for the purposeof spray width adjustment. Thus the opening 4 can be adjusted bydisplacing the segment aprons 9 and 10 (FIG. 3). The spraying width canbe affected by this. If, for example, the opening is displaced upward bychanging the cover 6, it is also possible to spray against the directionof gravity. It is important that the reservoir 29 remains on the bottom.

The pump disk 30 is formed coaxially on the centrifugal disk and isthereby fixedly connected with the centrifugal disk. The drive shaft 12is a part of a suitable motor 14.

The centrifugal wheel 1 and the pump disk 30 formed on it are fixedlyconnected with the drive shaft 4 by means of strips 15.

Finally, a feed opening 16 is provided, through which liquid to besprayed is guided into the housing 3 formed by the nozzle body 5 and thecover 6. In this chamber the pump disk 30 rotates in the direction ofthe arrow 19 (FIG. 3).

A view of the interior of the nozzle body 5 with feeding of the nozzlein accordance with arrow direction II in FIG. 1 is represented in FIG.2. As in the remaining figures, like elements are provided with the samereference numerals. Bars 23, 24 inside the nozzle body 5 are used forguiding the liquid.

Arrows 28 are additionally represented in FIG. 2 for explaining the flowpath of a liquid to be sprayed. The liquid is supplied supplied via aline system through the feed line 16 to the inner recess of the nozzlebody 5.

The liquid flowing in through the opening 16 is guided in the directionof the flow path 27 to the half-open beak-like embodied groove 13arranged in the center of the nozzle body 5, which is formed on the bars24. The liquid is then provided from the groove 13 to the inside of thecentrifugal disk 1.

Fed-in liquid is flung off the outer edge of the centrifugal wheel 1 bythe high speed. Individual droplet paths are indicated by the arrows 20(FIG. 3) drawn in dotted lines. It can be seen particularly clearly inthis view how the spraying width of the rotating nozzles can be changedby displacing the segment aprons 10 and 9 around the axis 2 in one ofthe directions of the arrows 21. The segment aprons 9 and 10 can befixed in place by means of arresting screws 18 after they have been set.

The flung-off liquid is caught over a greater part of the circumferenceby the cylindrical interior surface of the cover 6 (FIG. 3). Thisportion of the liquid is diverted by the surface 7 of the cover 6 andflows, following gravity, into the lower housing part of the nozzle body5, which is formed by the cylindrical surface 8 and is used as thereservoir 29. The liquid collected in the reservoir 29 enters the areaof the pump disk 30 through the opening 22, where it is picked up by thepump disk 30 to be again conveyed via the ramp 25 along the flow pathindicated by the arrow 26/28 into the upper area in order to be suppliedto the centrifugal disk 1 via the incline 11, groove 13, together withthe inflowing liquid.

FIG. 4 schematically shows the mode of functioning of the device. Avolume flow V1 is aspirated from a container B by means of thereversible metering pump P1 from the line L1 and is conveyed to thecentrifugal wheel 1. From there a partial volume V4 of the formed dropsis flung off. The rest is retained in the housing 3 and collected in thereservoir 29. The propulsion of the centrifugal disk 1 takes place bymeans of the motor 14 via the drive shaft 12. The volume flow V3 isconveyed from the reservoir 29 by means of the pump disk 30 and unitedwith the volume flow V1 and together with it again provided to thecentrifugal wheel 1. The alternate line path L3, represented in brokenlines, is also possible in place of the flow path 26, 28, which,however, requires a different behavior of the device, as described.

FIG. 5 shows an exploded representation of the device. Like elements areindicated therein by the same reference numerals. The axis 2, shown indash-dotted representation, indicates the coaxial association of theindividual parts.

Accordingly, the nozzle body 5 is mounted on the mounting plate 31.Furthermore, following insertion of the motor 14 into the cover 6 andslipping on the motor housing 34, they are combined into a furtherassembly group. The shaft 12 of the motor 14 is than fastened to thecentrifugal disk 1 by means of the coupling 32.

The seal 33 in the mounting gap between the motor housing 34 and thecover 6, as well as the compressed screw connection 35 for leading thecable 36 in, protect the motor from environmental effects. Following themounting of the segment aprons 9 and 10, the sub-assembly of the cover 6and the sub-assembly of the nozzle body 5 are screwed together.

In FIG. 5 the transfer of the liquid from the cover 5 to the centrifugalwheel 1 takes place by means of a transfer pipe 37, in whose center atapered cone, not shown, of the centrifugal wheel 1 rotates. Thissolution fulfills the same function as the groove 13, but has advantagesin case of liquids of high viscosity. In addition, the effect of theangular position is reduced. It will be understood that each of theelements described above, or two or more together, may also find auseful application in other types of constructions differing from thetypes described above.

While the invention has been illustrated and described as embodied in asegment rotary nozzle, it is not intended to be limited to the detailsshown, since various modifications and structural changes may be madewithout departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can, by applying current knowledge,readily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this invention.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended claims:
 1. A device for spraying a liquid,comprising a rotating surface having an axis of rotation; a housingpartially enclosing said rotating surface and having a circumferencewith an opening leaving a part of said circumference free; means forcollecting retained drops, said collecting means including a reservoir;a pump combining a collected liquid and flowing liquid, said pump havinga conveying surface which is located coaxially with said axis ofrotation of said rotating surface; a single rotating element, saidrotating surface and said conveying surface being parts of said singlerotating element, said axis of rotation of said rotating surface beinginclined at an angle with respect to a horizontal; and a metering pumpfor supplying liquid, said metering pump having a reversible conveyingdirection.
 2. A device as defined in claim 1, wherein said pump is afriction pump.
 3. A device as defined in claim 1, wherein said openingof said housing is adjustable.
 4. A device as defined in claim 1,wherein said opening of said housing has a position which is adjustable.5. A device as defined in claim 1, wherein said housing has an innerside and is provided on said inner side with bars for guiding a caughtliquid.